Heated wiper blade for motor vehicles and the like

ABSTRACT

A heated wiper blade for motor vehicles includes an elongated flexible beam and a heating element extending along the beam. The heating element may be configured to provide increased heat at the central portion of the blade and at the opposite ends of the blade. The heating element is comprised of an electrical conductor material that varies the amperage drawn between hot and cold ambient temperature operation. The flexible beam may include curved end portions and a flat or reduced curvature central portion. The heating element is preferably covered and sealed off to prevent loss of heat energy.

CROSS-REFERENCE TO RELATED APPLICATIONS AND CLAIM TO PRIORITY

This application is a continuation of and claims priority under 35U.S.C. § 120 to commonly owned, related U.S. patent application Ser. No.13/803,512, filed Mar. 14, 2013, now U.S. Pat. No. 9,533,656, issuedJan. 3, 2017, entitled HEATED WIPER BLADE FOR MOTOR VEHICLES AND LIKE,which is a continuation-in-part of and claims priority to U.S. patentapplication Ser. No. 13/177,382, filed Jul. 6, 2011, now U.S. Pat. No.9,003,595, issued Apr. 14, 2015, entitled HEATED WIPER BLADE FOR MOTORVEHICLES AND LIKE, which claimed priority under 35 U.S.C. § 119(e) toU.S. Provisional Application No. 61/361,628, filed Jul. 6, 2010, theentire disclosures of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

The present invention relates to windshield wiper blades for motorvehicles and the like, and in particular to an improved heated wiperblade and associated method.

Heated windshield wipers are generally known in the art, and includemany different forms and designs. Some such heated wiper blades heat thewiper frame, arm, and blade, or a combination of these members, using aheating element or some other type of added assembly. While such wiperblades are somewhat effective, they are inconvenient to both themanufacturer and the end user. For example, they are either very costlyto manufacture, thereby resulting in a high cost product that is passedthrough to the consumer, or they are very complex to install, therebyeliminating many of the do-it-yourself consumers. Also, such priordesigns fail to consider that the wiper should work effectively with thewindshield defrosting system of the motor vehicle as a fully integratedfunctional unit. Without the windshield defroster system, the windshieldwill freeze up with the accumulated snow and ice, creating a hazardoussituation.

A unique frameless heated wiper assembly is disclosed in U.S. Pat. No.7,721,382, the entire contents of which are incorporated by reference.While such wiper assemblies are generally effective, certainimprovements to the same would be advantageous.

SUMMARY OF THE INVENTION

One aspect of the present invention is a heated wiper blade for motorvehicles and the like having certain improvements to the inventiondisclosed in U.S. Pat. No. 7,721,382, as disclosed in greater detailhereinafter.

Yet another aspect of the present invention is to provide an improvedheated wiper blade and associated method that is economical tomanufacture, efficient in use, and particularly well adapted for theproposed use.

These and other advantages of the invention will be further understoodand appreciated by those skilled in the art by reference to thefollowing written specification, claims, and appended drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of a heating element of a heated wiper bladeaccording to one aspect of the present invention;

FIG. 2 is a schematic view of a heated wiper blade made of conductingmaterial;

FIG. 2A is a partially schematic view of a beam and heating elementaccording to another aspect of the present invention;

FIG. 2B is a partially schematic view of a beam and heating elementaccording to another aspect of the present invention;

FIG. 2C is a partially schematic view of a beam and heating elementaccording to another aspect of the present invention;

FIG. 3 is a partially fragmentary isometric view of a portion of a motorvehicle including a heated wiper blade assembly and system according tothe present invention;

FIG. 4 is a partially fragmentary, exploded isometric view of a heatedwiper blade according to one aspect of the present invention;

FIG. 5 is a partially fragmentary side elevational view of the heatedwiper assembly of FIG. 4;

FIG. 6 is a cross-sectional of the heated wiper blade of FIG. 5 takenalong the line 6-6;

FIG. 7 is a cross-sectional view of the heated wiper blade according toanother aspect of the present invention;

FIG. 8 is an exploded view of the heated wiper blade of FIG. 7;

FIG. 9 is a cross-sectional view of the heated wiper blade of FIG. 5taken along the line 9-9; FIG. 5;

FIG. 10 is a cross-sectional view of another version of the heated wiperblade of FIG. 9;

FIG. 11 is a side elevational view of a beam for heated wiperassemblies, wherein the beam has a flat center portion;

FIG. 12 is a plan view of the beam of FIG. 11;

FIG. 13 is an isometric view of a temperature sensing unit;

FIG. 14 is a partially schematic view of a first wiring harness;

FIG. 15 is a partially schematic view of a second wiring harness;

FIG. 16 is a partially schematic view of a third wiring harness;

FIG. 17 is a partially fragmentary isometric view of a portion of amotor vehicle including a heated wiper blade assembly and systemaccording to another embodiment of the present invention;

FIG. 18 is a partially fragmentary isometric view of a heated wiperblade according to of the present invention;

FIG. 19 is a partially fragmentary isometric view of a heated wiperblade according to the present invention; and

FIG. 20 is view of the circuit for the heated wiper blade according tothe present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

For purposes of description herein, the terms “upper,” “lower,” “right,”“left,” “rear,” “front,” “vertical,” “horizontal” and derivativesthereof shall relate to the invention as oriented in the attacheddrawing. However, it is to be understood that the invention may assumevarious alternative orientations and step sequences, except whereexpressly specified to the contrary. It is also to be understood thatthe specific devices and processes illustrated in the attached drawings,and described in the following specification, are simply exemplaryembodiments of the inventive concepts defined in the appended claims.Hence, specific dimensions and other physical characteristics relatingto the embodiments disclosed herein are not to be considered aslimiting, unless the claims expressly state otherwise.

The reference numeral 1 generally designates a heated wiper bladeembodying the present invention, which is schematically illustrated inFIG. 2. A heating element 2 is embedded in wiper blade 1 using a uniquepattern to achieve an improved distribution of heat and wipingperformance. More specifically, increased heat is provided in the center3 of the wiper blade 1 to compensate for wind. Also, increased heat isprovided at a section “W” (FIG. 2). Inner boundary 6 of W may be about0.5 inches from each end 4 of the blade 1 to compensate for the metalportion of the blade 1 not being in contact with the heating element 2,and because the heating element cannot be positioned all the way to theends of the beam. The illustrated heating element 2 has leads 5 disposedadjacent the center 3 of blade 1, which are connected with theelectrical power system of the associated motor vehicle.

Heater element 2 may comprise a Kapton or silicone etched foil adhesivebacked strip. Thermistor or other positive temperature coefficient (PTC)material on the foil strip facilitates regulation of the temperature ofthe blade 1, as discussed further below. Preferably, wiper blade 1 isgrounded, so that only the positive lead must be run under the hood ofthe vehicle to the heating element 2. Electrical power to the wiperblade 1 is preferably provided only after the ignition switch of thevehicle has been turned on. Airflow is sealed off on each side of thecenter 3 of the wiper blades 1 utilizing a sealant or other suitablematerial to prevent cooling of the heating element 2. A temperaturesensor 18 may be enclosed in metal casing, rather than being exposed tothe open air. The etched foil strip shown in FIG. 2 is a convenient wayto configure the heating element 2.

A graphite or graphite impregnated squeegee and/or rubber backing on thewiper blade 1 can be configured to have electrical power applied to heatthe squeegee and/or backing. Using graphite would electrically heatand/or assist heat transfer to the wiper blade 1.

In beam-type wiper blades, there is a spring metal that is curved whichfollows the curve of the windshield. This metal can be substituted withcarbon (graphite) that can be powered to produce heat for the wiperblade 1. Also, all of the metal brackets on current wiper blades can bemade using graphite instead of metal. In other words, a non-metal bladecan be heated by the electrical power of the motor vehicle.

Heated wire and/or etched foil heating tape can be embedded or extrudedduring the manufacturing process into the wiper bow, wiper bladebacking, and/or squeegee. The bow may be composed of metal, plastic,fiberglass, and/or graphite. The backing and squeegee may be composed ofrubber, embedded graphite, other materials, and/or other heat conductingmaterials.

A sensing and control module can be made for emergency vehicles of thetype normally stored inside buildings and maintained at roomtemperature, that is, around 70° F. In applications such as this, theheated wiper blades 1 are preferably on and ready for use at all times.For example, if the air temperature is 70° F., a normal heated blade mayget too hot if full power is supplied to the blade. Excessive power tothe blades may cause the blades to get too hot, resulting in melting ofrubber and/or plastic components. Thus, providing a module that reducesthe electrical power supplied to the heating elements of the blades toensure that the blades do not get too hot under such operatingconditions is preferred for applications where the vehicle is maintainedat room temperatures. The module includes a temperature sensor thatsenses the higher temperature of the storage area, and provides areduced voltage to the heated wiper blade 1 at higher (e.g., 70° F.)temperatures. For example, most motor vehicle battery and chargingsystems deliver 14.6 volts after the motor vehicle has been started andapproximately 12.6 volts when the motor vehicle is not running. However,the heated wiper blade 1 may only require 10.0 volts for proper heat at70° F. The control module may be configured to provide 11.0 volts if thetemperature is 30° F. and 13.0 volts at 0° F. Similarly, the controllermay be configured to shut off all electrical power to the blades if theair temperature exceeds 80° F. or other predefined temperature. Thisprovides a completely automatic system or mode that allows the heatedwiper blades to be left on at all times. PTC material, thermistor, orthermostat, etc., can be utilized to accomplish this function as well.

Reducing electrical power at increased temperatures can also beaccomplished to some extent by utilizing nickel 200 material for theheating element 2, such as those PTC materials where resistance changeswith temperature. As the ambient air temperature goes down, theresistance of the heating element wire or etched foil decreases and thecurrent increases, increasing the wattage of the heated wiper blade 1,thereby producing a higher temperature and a self regulating system, asdiscussed below.

FIG. 1 illustrates another way of manufacturing and connecting power tothe heated wiper blades. By making some or all of the parts of the bladeassembly from a conducting material, such as graphite, supplyingelectrical power to such parts causes them to heat. In FIG. 1, centerbracket 13, beam 14, and squeegee 15 are made of a conducting material.FIG. 1 also shows schematically how these components can be connected tothe power source by leads 5 such that electricity flows through thecomponents. It will be understood that the leads 5 may compriseinsulated wire that is routed along the blade to bracket 13, and furtherrouted along a wiper arms 10 (FIG. 3).

As discussed in more detail below, a wiring harness may be used toelectrically connect the heated wiper blade 1 to the electrical powersource. The wiring harness can be made in various ways, includingmolded, different wiring devices, crimps, connectors, inline splices,twist connectors, waterproof connectors, plug-in connectors, anddifferent wire lengths, sizes and colors. Different vehicles may needdifferent wiring harnesses to accommodate various heated wiper blades.In some vehicles, like fire trucks, UPS trucks, bread trucks, etc., thewipers extend down from the bulkhead of the vehicle. This would requirea different wiring harness with waterproof, ultraviolet-resistant wiresand connectors.

All wires connected to the heated wiper blades are preferably flexible,ultraviolet-resistant (sun), oil-resistant, and capable of carrying atleast five amps of current. All harnesses connected to the heated wiperblades also require a fuse.

A temperature sensor 18 may also be included with the wiring harness.The wiring harness may also include a module 17 and/or connectors thatconnect to the computer or processor associated with the motor vehicle,so that if the wires should fail or become disconnected, a warning lightor signal would alert the driver. Also, fuse holders, inline fuses,on/off switches, etc., could be included with the harness.

With further reference to FIG. 3, the heated wiper blades 1 are mountedto the existing arms 10 of a vehicle windshield wiper system. Theheating elements 2 of blades 1 are connected to wiring 22 utilizingdisconnectable connectors 25. Alternatively, the leads 5 of heatingelement 2 may be connected directly to wires 22. A manual switch 21 maybe disposed in the vehicle interior for operation by a user. Switch 21is connected to module 17 by a wire 23, and module 17 is connected tovehicle battery 16 by wire 19 and to vehicle ground by a wire 19 a. Inone embodiment, a temperature sensor 18 may be mounted directly behind avehicle grill 28 such that the temperature sensor 18 is exposed toambient air during vehicle operation. As discussed in more detail below,temperature sensor 18 may comprise a thermal mass to prevent abruptchanges in the sensed temperature. Temperature sensor 18 is operablyconnected to module 17 by wires 20. Different control arrangements andwiring harnesses are discussed in more detail below.

Referring again to FIG. 2, heating element 2 includes first and secondend portions 7 a and 7 b, respectively, each having a length “W.” Ingeneral, if the overall length A of heating element 2 and blade 1 is 18inches, B is preferably about 7.0 inches. If A is 21 inches, B ispreferably about 8.5 inches. If A is 23 inches, B is preferably about9.5 inches, and if A is 27 inches, B is preferably about 11.5 inches.Heating element 2 also includes a central portion 8 having a length “C,”and first and second intermediate portions 9 a and 9 b, respectively,each having a length “B.”

In the example illustrated in FIG. 2, the heating element 2 comprises afilm 31 having a conductive element 30 disposed on the film 31.Connectors 25 may be disposed at the ends of leads 5 to provide forconnecting and disconnecting leads 5 from wires 22 (see also FIG. 3)that operably connect the heating element 2 to battery 16 of thevehicle. Alternatively, wiring 22 may be permanently connected to leads5, and a suitable releasable connector (not shown) may be provided atmodule 17. The conductor 30 may comprise etched foil fabricated ofnichrome or other suitable conductive material. Preferably, conductor 30is a PTC material and comprises nickel 200 or other material having anelectrical resistance that is greater at higher temperatures, and lowerat lower temperatures. Use of a PTC conductor 30 provides for reducedheat production by the heating element 30 at higher ambient temperaturesto thereby prevent overheating and damage to the blade assembly thatcould otherwise occur. Although the resistance of conductor 30 may varydepending upon the needs of a particular application, testing of aheated wiper blade 1 including a nickel 200 conductor 30 shows thatconductor 30 may be configured to provide 1.74 amps at 0° F. and 1.4amps at 40° F. Thus, the use of a PTC material provides more amps(greater heat energy) at lower temperatures and fewer amps (lower heatenergy) at higher temperatures, even without a separate controller 17and temperature sensor 18 input.

The film 31 may comprise a Kapton style ribbon/tape, a PET film, a heavyfilm, or other suitable film material. Furthermore, heating element 2may comprise a silicone rubber sheet 31 having a conductor 30 disposedon the outside of the sheet 31, or the conductor 30 may be embedded inthe silicone rubber sheet 31. It will be understood that the conductor30 of FIG. 2 would appear in dashed lines if conductor 30 were imbeddedin a silicone rubber sheet 31.

Still further, conductor 30 may comprise a wire heating element made ofnichrome or nickel 200 or other suitable materials having an insulatingcover or sheath comprising Teflon, PVC, or other suitable material. Ingeneral, Teflon is preferred due to its higher temperature capabilities.An example of a wire having a conductor 30 with an insulating outercover or sheath is shown in FIG. 5a of U.S. Pat. No. 7,721,382

Conductor 30 may define a series of longitudinally extending portions 32and transversely extending portions 33. The longitudinally extendingportions 32 may have a reduced length at end portions 7 a and 7 bcorresponding to the dimension “W,” and also along the central portion 8having a dimension “C.” This provides a higher heat output in theregions 7 a and 7 b and c, relative to the intermediate portions 9 a and9 b. The conductor 30 may provide a heat output that can be expressed interms of heat energy per unit length of heating element 2. The closerspacing of transverse portions 33 of conductor 30 provides forsubstantially increased heat output per unit length at the end portions7 a and 7 b, and also at the central portion C of heating element 2.Because the conductor 30 may not extend all the way to the opposite endsof beam 14, the additional heat provided in end portions 7 a and 7 bcompensates for this and reduces build up of snow and ice at theopposite ends 4 of the wiper blade. Similarly, the increased heatprovided by the closer spacing of longitudinal portions 32 of conductor30 at the central portion C compensates for additional heat loss thatmay occur due to positioning of conductor 30 away from beam 14 atbracket 13. It will be understood that heating element 2 may provideincreased heat output per unit length at only the center portion C, orat one or both of the end portions 7 a and 7 b, or at both the centralportion C and the opposite end portions 7 a and 7 b.

With further reference to FIG. 2A, heating element 2 may comprise anelongated wire 35 that is disposed directly on an upper surface 36 ofbeam 14. Suitable retainers, adhesives, or clips 37 may be utilized tosecure the wire 35 to the beam 14. The wire 35 of heating element 2 maycomprise an elongated wire made of nickel 200, nichrome, or othersuitable conductive material that is encased in a sheath of insulatingmaterial such as PVC or Teflon. In general, wire 35 has an electricalresistance in the range of about 1-16 ohms per meter, depending upon thetotal length “A” of the beam 14, and the other requirements for aparticular application.

With further reference to FIG. 2B, heating element 2 may also comprisewires 40 that are secured to upper surface 36 of beam 14 utilizing clips37, adhesive, or the like in a manner that is substantially similar tothe arrangement discussed above in connection with FIG. 2A. Wire 40 maycomprise an inner conductor made of nickel 200, nichrome, or othersuitable material that is covered by an insulating material such asTeflon, PVC, or the like. In general, wire 40 may be substantially thesame as wire 35 discussed above in connection with FIG. 2A. Wire 40 mayinclude portions 41 a, 41 b, and 42 providing increased heat output perunit length of the blade at opposite end portions 7 a, 7 b, and atcentral portion 8. Portions 41 a, 41 b, and 42 may comprise a sine waveor the like providing increased heat per unit length at the oppositeends and central portions of the heating element 2 of FIG. 2B.

With reference to FIG. 2C, a heating element 2 c corresponding toanother aspect of the present invention includes a wire 45 that issecured directly to upper surface 36 of beam 14 utilizing clips 37 orother suitable connectors such as adhesives, or the like. Wire 45 may besubstantially the same as wires 35 and 40 discussed above in connectionwith FIGS. 2A and 2B, respectively. Wire 45 may form one or moreadditional loops 46 providing additional heat output at end portions 7 aand 7 b, and one or more additional loops 47 at central portion 8. Itwill be understood that a single loop 47 may be utilized with a U-bendend 38 (FIG. 2A), or wavy portions 41 a and 41 b (FIG. 2B). Similarly,the additional loops 46 (FIG. 2C) may be utilized in conjunction with awire having a straight central portion (FIG. 2A), or a wavy centralportion 42 (FIG. 2B). Also, any combination of the features shown inFIGS. 2, 2A, 2B, and 2C may be utilized to provide additional heat atonly the opposite ends 7 a and 7 b, only the central portion 8, or atthe end portions 7 a and 7 b and central portion 8.

With further reference to FIGS. 4 and 5, heated wiper blade 1 maycomprise a beam-type wiper blade having beam 14 and squeegee 15 that isconnected to beam 14. Beam 14 may include tabs 27 (see also FIG. 8) thatextend around opposite edges 29 a of squeegee 15 to thereby secure beam14 to squeegee 15. Other suitable connecting arrangements may also beutilized. Heated wiper assembly 1 also includes elongated covers 50 aand 50 b, a central cover 51, and a bracket 13 that is utilized tointerconnect the heat wiper blade 1 with an existing arm 10 of a vehiclewiper system. The beam 14, squeegee 15, covers 50 a, 50 b, and 51, aswell as bracket 13 may be substantially similar to commerciallyavailable beam type wiper blades. The covers 50 a, 50 b, and 51, as wellas squeegee 15 are preferably made of materials that can withstand200-300° F. Similarly, adhesives, sealants, filler material, and thelike also preferably comprise materials that can withstand temperaturesof 200-300° F. In general, beam-type blades made by variousmanufacturers are readily available from various retail outlets. Thecovers, beam, and squeegee will therefore not be described in detailherein, except as necessary to describe the differences between theheated wiper blade 1 of the present application and commerciallyavailable non-heated beam type wiper blades.

Wiper assembly 1 (FIGS. 4 and 5) further includes heating element 2which may be in direct contact with upper surface 36 of beam 14 asdescribed above in connection with FIGS. 2, 2A, 2B, and 2C. Heatingelement 2 may comprise any one of the heating elements described in moredetail above in connection with FIG. 2, 2A, 2B, or 2C. As discussedabove, heating element 2 may be connected to a module 17 utilizingwiring 22. It will be understood that some of the components of thewiring harness are not shown in FIGS. 4 and 5. When assembled, innerends 52 a and 52 b of covers 50 a and 50 b, respectively, are receivedin openings 53 a and 53 b of cover 51. Wiring 22 may pass throughopening 53 a or opening 53 b, and a heat resistant sealant 54 (FIG. 5)may be provided at openings 53 a and 53 b to provide an airtight sealbetween covers 50 a, 50 b, and cover 51. The heat resistant sealant 54is also utilized to provide an airtight seal around wires 22 where theyenter opening 53 a or 53 b.

With further reference to FIG. 6, a cavity 55 (see also FIG. 7) isformed by covers 50 a and 50 b. Heating element 2 is disposed in cavity55. Sealant 54 is utilized at edges 56 of cover 50 b to provide anairtight connection between cover 50 b, squeegee 15, and/or beam 14 suchthat cavity 55 is substantially airtight. Edge portions 56 of covers 50a and 50 b preferably include a tapered wedge-like surface 49 and a pairof inwardly-facing longitudinal grooves 48 (see also FIG. 8). Duringassembly, beam 14 is pushed into engagement with covers 50 a and 50 bsuch that opposite edges 24 of beam 14 engage tapered edges 49, and thensnap into inwardly-facing grooves 48 (See also FIG. 8). A sealant 54 orthe like is preferably disposed around the opposite side edges ofheating element 2 and/or beam 14 and/or squeegee 15 to provide anairtight seal as discussed below, sealant 52 may be disposed insidecovers 50 a, 50 b, and 51 (FIGS. 4 and 5). Covers 50 a and 50 b, beam14, squeegee 15, heating element 2, and sealant 54 are preferably madeof materials that are selected to withstand 200-300° F. Sealant 54 ispreferably a high temperature sealant that does not degrade at thehigher temperatures generated by heating element 2. The squeegee 15 isadhesively adhered, or otherwise mechanically connected, directly tobeam 14, whereby upper surface 26 of squeegee 15 is in direct contactwith lower surface 34 of beam 14 to thereby facilitate heat transferthere between. This also facilitates faster, more efficient assembly.

Cavity 55 may comprise an empty cavity as shown in FIG. 7, or sealant 52or a filler material 57 (FIG. 6) may be injected into cavity 55. Fillermaterial 57 may comprise a flexible sealant material that is capable ofwithstanding the higher temperatures resulting from heating element 2.In general, filler material 57 may be injected into cavity 55 in aliquid or highly viscous form, and the filler material 57 then cures toform a solid mass. Alternatively, covers 50 a and 50 b may comprise arelatively hard outer layer and filler material 57 that defines an innercore formed at the time the covers 50 a and 50 b are fabricated. Thecovers 50 a and 50 b and core 57 may be formed utilizing a moldingprocess or the like. The filler material 57 is significantly softer thanthe outer layer of the covers 50 a and 50 b. During assembly, the covers50 a and 50 b (with filler material 57) are snapped onto the beam asdescribed above. The filler material 57 pushes down on the heatingelement 2 and causes the heating element to contact upper surface 36 ofbeam 14, thereby ensuring that heat from heating element 2 istransferred into beam 14. Filler material 57 also insulates the upperside of the wiper blade to prevent heat loss. The outer shell and thecore filler material 57 may comprise rubber having significantlydifferent hardnesses, or the outer shell and the core may compriseentirely different materials. For example, the covers 50 a and 50 b cancomprise a relatively hard plastic, and the core 57 can comprise anelastomeric rubber. Also the outer surface of the covers 50 a and 50 bis preferably very smooth to prevent excessive buildup of snow and iceon the outside of wiper blades. Filler material 57 provides insulatingproperties such that more of the heat from heating element 2 istransferred to the beam 14 and to squeegee 15.

With reference to FIG. 9, bracket 13 may have a generally U-shaped crosssection with a lower flange or sidewall 59 and upwardly extendingflanges 58 a and 58 b. Lower flange 59 may be spaced apart from theupper surface 36 of beam 14 to form a gap 63. However, the gap 63 may betoo small to allow heating element 2 to be positioned therein betweenlower flange 59 and beam 14. Thus, heating element 2 may be disposed indirect contact with the upper surface 43 of lower flange 59 of bracket13. Gap 63 may be filled with filler material 57 to thereby provideincreased heat transfer from flange 59 to squeegee 15 adjacent bracket13.

With further reference to FIG. 10, heating element 2 may be disposedbetween lower flange or wall 61 of bracket 13 a and beam 14 if amodified bracket 13 a (see also FIG. 11) permit this configuration.

Bracket 13 a comprises a pair of generally upright side flanges 58 and58 b that are interconnected by an internal web or sidewall 61 or thelike to form a gap 62 that is large enough to receive heating element 2.Modified bracket 13 a permits heating element 2 to be disposed in directcontact with upper surface 36 of beam 14 where beam 14 extends throughor adjacent bracket 13 to thereby facilitate heat transfer from heatingelement 2 to beam 14 or 14 a and to squeegee 15 (see also FIG. 11).

With further reference to FIGS. 11 and 12, the beam may comprise a beam14 a having a substantially flat central portion 64 and curved outerportions 65 a and 65 b. In general, conventional beams 14 as shown inFIG. 4 have a uniform radius of curvature. This can tend to cause a gapbetween squeegee 15 and the windshield when the squeegee 13 is slidingover a portion of the windshield having less curvature. The straight orflat central portion 64 of beam 14 a ensures that the central portion ofsqueegee 15 stays in contact with the windshield surface. Also, straightor flat portion 64 reduces flexing of beam 14 a in operation, therebyreducing the tendency for heating element 2 to flex and break if heatingelement 2 is made from a material that cannot withstand repeatedflexing. In general, the overall nominal length “A” of heating element 2may be 18 inches, 21 inches, 23 inches, or 27 inches. The beam 14 istypically about 1 inch longer than heating element 2. The dimension “D”of flat central portion 64 of beam 14 a is preferably about 3-10 inches(depending in part, on the dimension “A,” and curvature of thewindshield). In a preferred embodiment, the dimension “D” is about 4.5inches. However, it will be apparent that the precise dimension of flatcentral portion 64 is not necessarily critical in all applications.

Beams 14 and 14 a may be formed from flat strips of metal by stamping orother such suitable process. In general, the curved outer portions 65 aand 65 b of beam 14 a have a radius of curvature that is similar to beam14 (see also FIG. 4). The flat central portion 64 can be created fromflat metal stock by curving only end portions 65 a and 65 b during thestamping or other forming process.

Beams 14 and 14 a may be made from spring steel or other suitable metal.Alternatively, beams 14 and 14 a may be formed from graphite, fiberglass, or a suitable polymer material. Furthermore, as noted above inconnection with FIG. 1, the beams 14 and 14 a may be made from aconductive material such that the beam 14 or 14 a itself acts as aheating element as described above in connection with FIG. 1. If thebeam 14 or 14 a is used as a heating element, a separate heating element2 is not required. Referring again to FIG. 4, other components of wiperblade assembly 1, such as the covers 50 a, 50 b, 51, and bracket 13 mayalso be made of a conductive material and are operably interconnectedwith an electrical power source, whereby these components also provide aheating function. In general, these components may be made of a metalconductive material or they may comprise a conductive plastic material.Conductive plastic material may comprise a plastic resin that has beenembedded with carbon powder or fiber to reduce the electricalresistivity of the plastic material. Plastic that has been formulatedwith stainless steel fiber, inherently dissipative polymer, or othersuch materials may also be utilized.

Beams 14 and 14 a may comprise an extruded polymer material, andconductor 30 may comprise an etched foil heating tape that is imbeddedor extruded into the beam 14 or 14 a. Conductors 30 may be extruded intothe beam 14 or 14 a. The spring beam may also comprise a carbon fibermaterial with conductor 30 extruded therein. The conductor 30 maycomprise a nickel 200 material, nichrome, or other PTC resistancematerial. Leads 5 interconnect conductors 30 with the other wiring inthe system. Leads 5 may protrude transversely from flat center portion64, or from opposite ends 4 a of beam 14 a.

Heated wiper blade 1 may comprise a beam-type wiper having a pair ofspring steel spines that connect to an elongated blade as shown in U.S.Pat. No. 7,721,382. The beam 14 may comprise a slotted elastic member asdisclosed in U.S. Patent Publication No. 2006/0026786, the entirecontents of which are hereby incorporated by reference. If the squeegeehas an upper surface that is above the upper surface of the beam orbeams (i.e., the beams are received in slots on opposite sides of thesqueegee), the heating element may be secured directly to the uppersurface of the squeegee utilizing adhesive, adhesive sealant, or thelike to ensure that heat from element 2 is transferred into thesqueegee.

With further reference to FIG. 13, temperature sensor 18 may comprise ablock 66 that is made of aluminum or other material having significantthermal energy storage capabilities. A hole or bore 67 is formed inblock 66, and a sensor element 68 is positioned in the bore 67 withwires 20 extending out of bore 67. Sealant 69 may be disposed in bore 67to provide a watertight seal around wires 20 and to retain sensorelement 68 in bore 67. If bore 67 extends all the way through block 66to form an open end 70, the open end 70 may also be filled with sealant69. Block 66 has a length X, a height Y, and a width Z. In general, thedimensions X, Y, and Z are chosen to insure that block 66 has sufficientthermal mass to prevent rapid temperature fluctuations of sensor element68. If the block 66 is made of aluminum, the length X may be about 1.5inches, and the height and width may be about 1 inch. Block 66 may bevarious shapes, including cylindrical or other suitable shapes.

With reference to FIG. 14, a wiring harness 75 includes a battery 16, amodule 17, a temperature sensor 18 and connectors 25 a that releasablyinterconnect wiring 22 with leads 5 of heating elements 2 of heatedwiper blades 1. The electrical connectors 25 a may be positionedadjacent an end of arm 10 (see also FIG. 3). If the heated wiper bladeassemblies 1 are retrofitted to a vehicle, the module 17, thetemperature sensor 18, and wiring 19, 22, and 23 may be installed in avehicle, and connectors 25 a may be utilized to releasably interconnectharness 75 with heated wipers 1. If one of the heated wipers 1 requiresreplacement, it can be quickly and easily disconnected and replaced bydisconnecting a connector 25 a from the wiper blade being replaced,followed by interconnecting of connectors 25 a to the replacement blade1. In this way, once a vehicle has been retrofitted with the wipersystem, only the blade portion of the system needs to be replaced in theevent one of the heated blades 1 does not function properly.Alternately, a single connector 25 b and wire 22 b may be utilized tointerconnect wiring 22 with module 17. Connectors 25 a and/or 25 b arepreferably waterproof, 7 amp rated connectors having a very smallexternal size to reduce the visual effects of connector 25 a.Furthermore, if connector 25 b is very small, a hole in seal 76 (FIG. 3)can be formed, and connector 25 b can be passed through the hole. Ifrequired, sealant can be applied around the hole through seal 76. Thisreduces disruption of the seal around the vehicle hood.

A wiring harness 85, similar to the wiring harness 75 of FIG. 14,further includes a connector 81 that may be utilized to interconnect thewiring harness to a vehicle fuse box. Alternatively, a fuse 79 and fuseclip 80 may be utilized. The portions of wiring harnesses 75 and 85 thatare subject to flexing during use (i.e., the portions directly adjacentarms 10) are preferably made of a flexible wire that retains itsflexibility to at least −40° F. and more preferably retains itsflexibility to −76° F.

All of the connectors, wire splices, butt splices, and other componentsof the wiring harness are preferably moisture and waterproof.Furthermore, all of the wire and connectors preferably meet automotivespecification such as TXL wire for portions of the wire that aredisposed in the engine compartment and below the hood of the vehicle.The wires to the wiper blades 1 are preferably about 0.125 inches indiameter, and not less than 40 inches long, flexible, remaining flexibleto −65° F. As discussed above, the wires can be connected at the wiperblades 1, or under the hood of a vehicle. If the connectors are locatedunder the hood, there is less chance of damage to the connectors fromcar washes, wind, or the like. Also, as discussed above, the wirerunning to the wiper blades 1 must be replaced with the wipers if anunder-hood connection is utilized. Thus, providing a connector at thewiper generally provides for a lower cost wiper blade, and facilitatesreplacement in general. The system is configured to provide power to theheated wiper blades 1 only if the vehicle ignition switch is on.Furthermore, with the electrical system grounded on the wiper arms 10,only a positive lead wire needs to be run under the hood of a vehicle.

Module 17 may be configured to control the amount of electrical currentsupplied to heating elements 2 based on an ambient temperature sensed bytemperature sensor 18. Module 17 is configured, in part, to account forthe material utilized to make the heating element 2. With reference toFIG. 16, module 17 may comprise sensors 18 a and 18 b. First sensor 18Acloses at approximately 0° F., while sensor 18B closes at approximately40° F. The 40° F. sensor 18B has a dropping resister 100 that reducesthe voltage to approximately 10.6 volts, from the 13.6 volts provided bya motor vehicle alternator during operation. Thus, the circuit causesless voltage and heat at the blade when the temperature exceeds 0° F.Although the 10.6 volt provides good operation in the temperature rangeof 0° F. to 40° F., additional heat is required when the operatingconditions are below about 0° F. When the ambient temperature is 0° F.or lower, the second sensor 18B bypasses the dropping resister 100,whereby the heating element 2 of the wiper receives 13.6 volts. When13.6 volts is supplied to the heating element 2, the wiper bladeassembly 1 can be operated at temperatures between about −40° F. and 0°F., while preventing excessive heat (and attending damage) at operatingtemperatures from about 0° F. to about 40° F.

The module 17 thus acts as a voltage regulator. For example, module 17may be configured to provide 8 to 10 volts to the heating element 2 whenthe ambient temperature reaches 40° F. As temperatures drop below 40°F., the module 17 is configured to regulate the voltage up to 13.6volts.

Module 17 may alternatively comprise a Pulse Width Modulator (PWM) thatis supplied with the vehicle at the time it is manufactured, orretrofitted to a vehicle. PWM may also comprise an aftermarket unit thatis retrofitted to a vehicle and may be used with or without PTCsensor/heating element, or other sensing means. Furthermore, a motorvehicle may include a temperature sensor at the time it is manufactured.If the on-board motor vehicle includes an original equipmentmanufacturer (OEM) PWM and temperature sensor, module 17 can beconfigured to control voltage to heating element 2 to account forambient operating conditions. For example, the PWM may be configured toprovide electrical current to heating element 2 when the ambienttemperature is 40° F. or lower, and the electrical current may besupplied to the heating element 2 until a temperature inside the bladeas sensed by a temperature sensor exceeds about 150° F., at which pointthe PWM provides reduced current to prevent overheating of the heatingelement 2 and other components. As the temperature of the blade drops,it is contemplated that the PWM may provide less current (fewer pulses)until the temperature stays at approximately 150° F. even if the ambienttemperature is −40° F.

Another aspect of the present disclosure that is particularly useful isthat it provides a fully self-regulating heating element 2 for the wiperblade 1. FIG. 17 depicts such a system for a fully self-regulatingheating element 2 for the wiper blade 1, especially in the case ofaftermarket installations. It has been found that a PTC conductor 30having a variable resistance can be employed, such that at an ambienttemperature of 40° F. and below and system voltage of 12 to 16 volts,the blades do not exceed a predetermined maximum temperature, preferably150° F. In operation, with the voltage only delivered at temperaturesbelow 40° F., the temperatures at which icing and freezing of the wiperblade 1 can occur, the PTC material causes the electrical resistance ofthe conductor 30 to lower in accordance with lower ambient temperatures,thereby providing increased heat from the conductor 30 such that theexterior surfaces of the wiper blades 1 tends to stay at approximatelythe same temperature, without control by a separate controller andtemperature sensor.

The specific resistance level of the conductor 30 will generally dependon the configuration of the various components, such as the beam 14 andcovers 50 a and 50 b, as well as the presence or absence of fillermaterial 57 (see, e.g., FIG. 6). Thus, no two systems are the same andthe proper resistance level for the heating element 2 must be determinedby testing different conductors 30, until the proper resistance level(resistance per unit length) provides an appropriate temperature rangeexperienced at the exterior of the blade (preferably betweenapproximately 125° F. to 150° F. when the ambient temperature is 0° F.to 40° F.) and not to exceed 150° F. At more extreme cold temperatures(e.g., between −40° F. and 0° F.), obviously the exterior bladetemperature may fall below 125° F. As discussed above, in general,conductor 30 will have a resistance in the range of approximately 1-16ohms per meter, if conductor 30 comprises a wire having a conductiveelement made from PTC material such as nickel 200 or other conductivematerial and an insulating sheath made of Teflon, PVC, or the like.

For the automatic, self-regulated heated wiper system, the manual switch21 and wire 23 can optionally be omitted. Rather, as shown in FIG. 17,the temperature sensor 18 is preferably combined with module 17 andsituated just below the windshield to allow power to the wiper blades 1only when the temperature sensor 18 detects an ambient temperature ofless than 40° F. That is, module 17 in combination with temperaturesensor 18 acts as a simple on/off switch. Once the temperature dropsbelow 40° F. and the power is switched on, the current flow though theheating element 2 is self-regulating. The module 17 of theself-regulating system also saves space, as it requires a volume of only1.25 inch by 1.5 inch by 0.5 inch.

The temperature sensor 18 may be located between the hood 11 (whenclosed) and the bottom of the windshield 12. Alternatively, thetemperature sensor 18 can be attached to the windshield 12. Thus, asingle temperature sensor 18 can be employed for both wiper blades 1.Moreover, the wiring harness 22 for the system can be simplified to twoconnectors 25, one for each wiper blade 1, and a connector 25 b thatgoes to the wiring harness of the module 17.

Alternatively, the temperature sensor 18 can be spliced into the wire 22extending between the wiper blade 1 and the hood 11. That is, thetemperature sensor 18 may be incorporated into the wiring 22 to thewiper blade 1 (see, i.e., FIG. 18). Preferably, each wiper arm 10 housesa temperature sensor 18, as shown in FIG. 19, which can be molded,covered, or otherwise provided with a thermal mass for thermal energystorage to prevent rapid temperature changes, thereby creating aninaccurate temperature signal, as discussed above. In the case of newmotor vehicles, the temperature sensor 18 may already exist and thepresent system can be wired into the motor vehicle's existing system.However, there are disadvantages with wiring the wiper through thevehicle electrical system, in that voltage drops may occur from usingthe electricity from the vehicle's electrical system.

Rather, a benefit of the disclosed self-regulating system is that it canbe wired directly to the battery. Thus, the voltage delivered to theheating elements 2 is maximized and voltage drops that may occur fromusing the electricity from the vehicle's electrical system areeliminated. It has also been found that when using an OEM remotestarter, some motor vehicles use a wiring platform will not energize thecircuit when the vehicle is started. Moreover, some circuits shut off incertain conditions when the vehicle is running. Connecting theself-regulating system directly to the battery avoids theseshortcomings.

Preferably, the self-regulating system is provided with self diagnosticLED light 95 on the module 17 that illuminates when voltage is suppliedto the wiper blade 1. The self-regulating system also is preferablyprovided with an electronic fuse 96 (such as that manufactured byPolyfuse) that protects the system from shorts or overloads. When theshort circuit is resolved, such fuses automatically reset. Thus, the useof electronic fuses avoids the need to replace traditional fusiblelinks.

Due to the simplicity of the self-regulating system, there are onlythree wires required, as shown in FIG. 20. The first wire 19 isconnected to the positive post 93 on the battery 16. The second wire 19a is connected to the negative post 91 of the battery or ground, or, inthe case of grounding to the wiper blade 10, to the wiper blade 10. Thethird wire 22 is connected to the heating elements 2 of the wiper bladeas discussed above. A power switch 97 is controlled by the temperaturesensor 18 and closes the circuit to allow power to the heating element 2at temperatures below 40° F. A voltage comparator 98 and voltagereference 99 are connected with power switch 97 in the circuit. As notedabove, most motor vehicle battery and charging systems deliver 14.6volts after the motor vehicle has been started and approximately 12.6volts when the motor vehicle is not running. Thus, the voltagecomparator 98 compares the voltage in line 19 to the reference voltage99, and actuates power switch 97 when the voltage drops below apredetermined level, such as preferably 13.0 volts, so that power is cutoff to the self-regulating system when the motor vehicle is notoperating. Optionally, although not required, a manual switch 21 can beadded to the circuit.

Several advantages can be realized through the aforementionedself-regulating system. First, as noted above, at colder ambienttemperatures, the amperage drawn by the heating element increases toincrease the heat output of the heating element 2 and to therebymaintain the external temperature within an acceptable temperature,preferably not to exceed 150° F. Also, the self-regulating systemdisclosed herein has been found to heat up approximately twice as fastas heated blades without PTC materials. Further, as the motor vehiclemoves faster in colder weather, the air flow over the wiper blades 1tends to cool the heated wiper blades 1. As this happens, the PTCmaterial will draw more amperage, causing the wiper to increase heatoutput and re-warm the blade 1. As the wiper blade 1 reaches the desiredtemperature, the PTC material will draw less amperage, preventing thewiper 1 from getting too hot. Finally, the self-regulating systemdisclosed herein allows the system to be easily wired without the use ofthe motor vehicle electrical platform or system. It requires just apositive lead 19 to the wiper 1, relying on the negative ground 19 a ofthe wiper to complete the circuit to the battery 16.

As an aspect of the present disclosure, it has been found that the useof PTC material is advantageous (in tape and wire form) for the smallspace of the wiper blade 1 to obtain self-regulation. It has also beenfound that winding or thickening the PTC material improvesself-regulation. Providing a maximum heating surface area or materialgives a wider range of amperage between hotter and colder ambienttemperature operation. For instance, with smaller heating surfaces ofthe heating element 2, the amperage differential between hotter andcolder ambient temperature operation is only a few tenths of an amp. Bymaximizing the heating surface of the heating element 2, approximately a1.1 amp differential between hotter and colder ambient temperatureoperation can be obtained for a 16-inch blade. That is, a 16-inch bladehaving a heating element 2 constructed from PTC materials and with anincreased heating surface area draws 1.3 amps or higher when fullyheated. When cold, the same 16-inch blade draws 2.4 amps or moredepending on the temperature, resulting in a 1.1 amp differential. Inthe case of a 28-inch blade, a differential of approximately 1.6 ampscan be obtained. That is, a 28-inch blade with a heating element 2constructed from PTC material and having a maximized surface area whenfully heated draws about 1.76 amps. When cold, it will draw 3.36 amps ormore depending on the temperature. Colder temperatures result biggerdifferentials. This, of course, would vary depending on how heavy orlight the blades are manufactured. The ability to draw greater amperagesat lower temperature significantly improves the performance of theheated wiper blade 1, decreases the time necessary for it to heat up,and causes the external temperature of the heated wiper blade 1 to beautomatically maintained between an acceptable temperature range,preferably not to exceed 150° F.

It has also been learned that not only the amount of PTC material andthe surface area of the heating element make a difference, but also thatthe thickness of the coating, whether made of PVC, tefzel, cambridge,kapton, butyl rubber, etc., is a factor. If the material is too thick,the PTC material warms up to the desired temperature, but outputs lessheat. If the coating is thinner or of a type that releases heat faster,greater differentials in the amperage change can be realized.

The PTC material can be in either wire or tape form and can be straight,coiled, sinuous, etc., as noted above. Preferably, the heating element 2made of the aforementioned PTC material is made of a wire winding ofnickel 200 having a thickness of 0.080 inch and having 24 to 34 windingsper inch.

Thus, self-regulating heated wiper blades can be obtained and requiresthe balance of several factors: the area of the heating surface; the PTCmaterial (nickel 200 works best, but stainless steel, silver, nichrome,nickel, nickel in combination with copper, iron, kanthal, PTC ceramic,and or lean nickel also are useful); the thickness and type of coatingmaterial (such as whether the heating tape or wire is touching or gluedto the metal beam, cover, and squeegee and whether an air space isprovided); the blade size (the size and mass of the blade used) and theamount of material or the type of blade (nearly every blade lengthrequires a different resistance per foot of heating elements and whetherthe material is straight with a relatively large surface area, sinuouson a tape, or wound wire with as many windings as possible); and thevoltage supplied to the system (typically 12.5 volts to 16 volts, wherethe higher the voltage, the bigger the differential or sensitivity totemperature).

An important consideration is that for each length, size, or mass, theamount of resistance per foot must be balanced. There should be as muchheating surface area of the heating elements as possible. The coating ofthe heating element should be thin enough so the heating element doesnot simply warm up and slow the rate at which the current is beingdrawn, but not so thin that the wire or tape becomes too hot on thesurface and burns the material of the blade. The self-regulating systemdisclosed therein essentially becomes a voltage regulator (without theadditional expense and weight) and thus ensures that the heating element2 is provided with the maximum amount of voltage from the battery of thevehicle.

In the foregoing description, it will be readily appreciated by thoseskilled in the art that modifications may be made to the inventionwithout departing from the concepts disclosed herein. Such modificationsare to be considered as included in the following claims, unless theseclaims by their language expressly state otherwise.

The invention claimed is:
 1. A heated wiper blade assembly for vehiclewindshields, wherein the heated wiper blade assembly comprises at leastone elongated curved beam conforming to a windshield, a bladeoperatively coupled with the elongated curved beam, a bracketoperatively coupled to a central portion of the elongated curved beam,wherein the bracket is configured to releasably connect the heated wiperblade assembly to an arm of vehicle windshield wiper system, anelectrical resistance heater comprising an elongated electricalconductor that produces heat when electrical current supplied by abattery having a positive battery voltage is passed there through, and acontroller; wherein the controller comprises an electrical circuithaving an electrical current supply input in electrical communicationwith the positive battery voltage and having an input voltage equivalentto the positive battery voltage, an electrical current output having anoutput voltage variable between a first non-zero output voltage and asecond non-zero output voltage, a temperature sensor disposed betweenand in electrical communication with the electrical current supply inputand the electrical current output, and an electrical resistor disposedbetween the electrical current supply input and the electrical currentoutput arranged in parallel electrical communication with thetemperature sensor, wherein the temperature sensor is operable betweenan open and closed condition in association with a predeterminedtemperature and the temperature sensor when in the closed conditionobtains the first non-zero output voltage below the first predeterminedtemperature and when in the open condition obtains the second non-zerooutput voltage above the first predetermined temperature.
 2. The heatedwiper blade assembly of claim 1, wherein the circuit further comprises asecond temperature sensor disposed between the electrical current supplyinput and the electrical resistor, wherein the second temperature sensoris operable between an open and closed condition in association with asecond predetermined temperature and the temperature sensor when in theclosed condition obtains the second non-zero output voltage and when inthe open condition obtains a third output voltage.
 3. The heated wiperblade assembly of claim 2, wherein the first predetermined temperatureis 0° F. and the second predetermined temperature is 40° F., and thefirst non-zero output voltage is 13.6 V, the second non-zero outputvoltage is 10.6 V, and the third output voltage is 0 V.
 4. The heatedwiper blade assembly of claim 1, wherein electrical conductor has anelectrical resistance that varies with the temperature of the electricalconductor, whereby the electrical resistance heater provides greaterheat energy at a first lower ambient temperature than at a second higherambient temperature.
 5. The heated wiper blade assembly of claim 4,wherein the material for the electrical conductor is selected from thegroup consisting essentially of nickel and its alloys, stainless steel,silver, copper, iron, kanthal, and PTC ceramic.
 6. The heated wiperblade assembly of claim 5, wherein the material for the electricalconductor comprises nickel
 200. 7. The heated wiper blade assembly ofclaim 1, wherein the controller actuates the electrical resistanceheater in response to operation of the motor vehicle.
 8. A heated wiperblade assembly for vehicle windshields, wherein the heated wiper bladeassembly comprises at least one elongated curved beam conforming to awindshield, a blade operatively coupled with the elongated curved beam,a bracket operatively coupled to a central portion of the elongatedcurved beam, wherein the bracket is configured to releasably connect theheated wiper blade assembly to an arm of vehicle windshield wipersystem, an electrical resistance heater comprising an elongatedelectrical conductor that produces heat when electrical current suppliedby a battery having a positive battery voltage is passed there through,and a controller; wherein the controller comprises an electrical circuithaving an electrical current supply input in electrical communicationwith the positive battery voltage and having an input voltage equivalentto the positive battery voltage, an electrical current output having anoutput voltage variable between a first non-zero output voltage and asecond non-zero output voltage, and a voltage regulator disposed betweenthe electrical current supply input and the electrical current outputand in operable electrical communication with a temperature sensor,wherein the first non-zero output voltage is obtained below a firstpredetermined temperature and the second non-zero output voltage isobtained above the first predetermined temperature.
 9. The heated wiperblade assembly of claim 8, wherein the voltage regulator is an analogrheostat.
 10. The heated wiper blade assembly of claim 8, wherein thevoltage regulator comprises a digital voltage regulator.
 11. The heatedwiper blade assembly of claim 8, wherein the voltage regulator comprisesa pulse width modulator.
 12. The heated wiper blade assembly of claim11, wherein the pulse width modulator provides a first non-zero currentto the elongated electrical conductor at ambient temperatures between40° F. to 0° F.
 13. The heated wiper blade assembly of claim 12, whereinthe pulse width modulator provides a second non-zero current to theelongated electrical conductor at a current higher than the firstcurrent at ambient temperatures between 0° F. to −40° F.
 14. The heatedwiper blade assembly of claim 11, wherein the pulse width modulatorprovides electrical current to the elongated electrical conductor whenthe ambient temperature is 40° F. or lower and electrical current issupplied to the elongated electrical conductor until the temperature ofthe blade as sensed by a second temperature sensor exceeds about 150°F., at which temperature the pulse width modulator provides reducecurrent to the elongated electrical conductor to prevent overheating ofthe elongated electrical conductor.
 15. The heated wiper blade assemblyof claim 14, wherein the pulse width modulator controls the voltage sothat as the temperature of the blade drops, the pulse width modulatorprovides current to the elongated electrical conductor at a firstnon-zero current until the temperature of the blade reachesapproximately 150° F. at ambient temperatures between 40° F. to 0° F.16. The heated wiper blade assembly of claim 15, wherein the pulse widthmodulator controls the voltage so that as the temperature of the bladedrops, the pulse width modulator provides a second current to theelongated electrical conductor higher than the first current until thetemperature of the blade reaches approximately 150° F. at ambienttemperatures between 0° F. to −40° F.
 17. The heated wiper bladeassembly of claim 8, wherein the electrical circuit further comprises avoltage sensor by which the circuit senses the positive battery voltageand the circuit allows current flow to the elongated electricalconductor only when the circuit senses that the positive battery voltagecorresponds with a battery voltage obtained during operation of themotor vehicle and prevents current flow to the elongated electricalconductor when the battery voltage drops below the positive batteryvoltage corresponding with a battery voltage obtained during operationof the motor vehicle.
 18. The heated wiper blade assembly of claim 8,wherein the circuit further comprises one or more LEDs in electricalcommunication with the electrical resistance heater and wherein the oneor more LEDs are actuated by current flow.
 19. The heated wiper bladeassembly of claim 8, wherein the controller actuates the electricalresistance heater in response to operation of the motor vehicle.
 20. Theheated wiper blade assembly of claim 8, wherein the heated wiper bladeassembly further comprises a cover extending over portions of theelectrical resistance heater and the elongated curved beam and theelectrical resistance heater is disposed between the cover and the bladeoperatively coupled with the elongated curved beam.
 21. A heated wiperblade assembly for vehicle windshields, wherein the heated wiper bladeassembly comprises at least one elongated curved beam conforming to awindshield, a blade operatively coupled with the elongated curved beam,a bracket operatively coupled to a central portion of the elongatedcurved beam and configured to releasably connect the heated wiper bladeassembly to an arm of vehicle windshield wiper system, an electricalresistance heater comprising an elongated electrical conductor thatproduces heat when electrical current supplied by a battery having apositive battery voltage is passed there through, and a controllerconfigured to control the electrical power supplied to the heatingelement based, at least in part, on ambient temperature, and wherein thecontroller provides a first voltage at above a first ambienttemperature, and a second voltage when the ambient temperature is belowthe first temperature but above a second ambient temperature, and athird voltage when the ambient temperature is below the second ambienttemperature.
 22. A heated wiper blade assembly for vehicle windshields,wherein the heated wiper blade assembly comprises at least one elongatedcurved beam conforming to a windshield, a blade operatively coupled withthe elongated curved beam, a bracket operatively coupled to a centralportion of the elongated curved beam, wherein the bracket is configuredto releasably connect the heated wiper blade assembly to an arm ofvehicle windshield wiper system, an electrical resistance heatercomprising an elongated electrical conductor that produces heat whenelectrical current supplied by a battery having a positive batteryvoltage is passed there through, a cover extending over portions ofelectrical resistance heater and the elongated curved beam and theelectrical resistance heater disposed between the cover and the bladeoperatively coupled with the elongated curved beam, and a controller;wherein the controller comprises an electrical circuit having anelectrical current supply input in electrical communication with thepositive battery voltage and having an input voltage equivalent to thepositive battery voltage, an electrical current output having an outputvoltage variable between a first non-zero output voltage and a secondnon-zero output voltage, and a voltage regulator disposed between theelectrical current supply input and the electrical current output and inoperable electrical communication with a temperature sensor, wherein thefirst non-zero output voltage is obtained below a first predeterminedtemperature and the second non-zero output voltage is obtained above thefirst predetermined temperature.
 23. The heated wiper blade assembly ofclaim 22, wherein the electrical circuit further comprises a voltagesensor by which the circuit senses the positive battery voltage and thecircuit allows current flow to the elongated electrical conductor onlywhen the circuit senses that the positive battery voltage correspondswith a battery voltage obtained during operation of the motor vehicleand prevents current flow to the elongated electrical conductor when thebattery voltage drops below the positive battery voltage correspondingwith a battery voltage obtained during operation of the motor vehicle.24. A heated wiper blade assembly for vehicle windshields, wherein theheated wiper blade assembly comprises at least one blade conforming to awindshield, an electrical resistance heater comprising an elongatedelectrical conductor that produces heat when electrical current suppliedby a battery having a positive battery voltage is passed there through,and a controller; wherein the controller comprises an electrical circuithaving an electrical current supply input in electrical communicationwith the positive battery voltage and having an input voltage equivalentto the positive battery voltage, an electrical current output having anoutput voltage variable between a first non-zero output voltage and asecond non-zero output voltage, and a voltage regulator disposed betweenthe electrical current supply input and the electrical current outputand in operable electrical communication with a temperature sensor,wherein the first non-zero output voltage is obtained below a firstpredetermined temperature and the second non-zero output voltage isobtained above the first predetermined temperature.
 25. The heated wiperblade assembly of claim 24, wherein the voltage regulator is an analogrheostat.
 26. The heated wiper blade assembly of claim 24, wherein thevoltage regulator comprises a digital voltage regulator.
 27. The heatedwiper blade assembly of claim 24, wherein the voltage regulatorcomprises a pulse width modulator.
 28. The heated wiper blade assemblyof claim 24, wherein the heated wiper blade assembly further comprisesat least one elongated curved beam conforming to a windshield, the bladeoperatively coupled with the elongated curved beam, a bracketoperatively coupled to a central portion of the elongated curved beam,wherein the bracket is configured to releasably connect the heated wiperblade assembly to an arm of vehicle windshield wiper system, and a coverextending over portions of the electrical resistance heater and theelongated curved beam and the electrical resistance heater is disposedbetween the cover and the blade operatively coupled with the elongatedcurved beam.
 29. The heated wiper blade assembly of claim 28, whereinthe heating element is disposed between the blade and the cover.
 30. Theheated wiper blade assembly of claim 29, wherein the heating element isin direct physical contact with the blade.
 31. The heated wiper bladeassembly of claim 28, wherein the heating element is embedded orextruded in the heated wiper blade assembly.
 32. The heated wiper bladeassembly of claim 31, wherein the heating element is embedded orextruded in the blade.
 33. The heated wiper blade assembly of claim 28,wherein the heating element is embedded in a plastic or fiber flexiblewiper bow.
 34. The heated wiper blade assembly of claim 28, whereineither or both of the blade and beam is extruded.